Bats from scats: Using eDNA to safely identify protected bat species in a time of COVID-19

April 17, 2020 Kim Wenborn

In a time of pandemic, how can we reduce risks to human health while also protecting threatened and endangered bat species?

 

Today, April 17, is International Bat Appreciation Day, the day when we all stop to appreciate the vital contribution bats make to healthy ecosystems. All right, before you cringe, let me dispel a few myths: Bats do not want to suck your blood. Bats will not transform into vampires or werewolves, and they are not plotting to swoop down and nest in your hair.

In fact, bat species—and maintaining a healthy biodiversity of bat species—are good for the planet. Bats perform many essential functions in healthy ecosystems, including insect control, and as pollinators, seed spreaders, and re-foresters. I’ll bet you thought that was just a job for the birds and the bees. Not so.

In some areas, bats are indicators of ecological health, in that a change in their presence or abundance signals a shift in biodiversity and quality of habitat.

Unfortunately, bats have been receiving a lot of negative attention lately, more than usual, because Asian horseshoe bats have been identified as a potential source of SARS-CoV-2, the coronavirus responsible for COVID-19. The theory is that SARS-CoV-2 spread from Asian horseshoe bats to another species that transmitted the virus to humans.

 

Managing bats is about more than pest control. Remember, many bat species are protected.

 

Now, there is a potential for humans to spread SARS-CoV-2 to other bat species, specifically bats that are already suffering from white-nose syndrome, a disease caused by fungal infection in bats’ noses that has decimated bat populations in North America and has been dubbed the most devastating wildlife disease of mammals in recorded history. According to a recent story published by the Canadian Broadcasting Corporation (CBC), while the risk of transmission from humans to bats is relatively low in North America, the results could be devastating for both humans and bats.

All that said, sometimes bats end up in places where they don’t belong—like roosting in residential or commercial buildings. Bats are adapting to make use of man-made structures for _q_tweetable:Now, more than ever, it’s important to limit interactions between humans and bats to prevent the spread of the new coronavirus; we are all in this together, bats and humans alike._q_roosting to replace their natural habitat that has been destroyed and degraded by human development. While there are some human health risks associated with bats in buildings, it is our job to help clients reduce these risks and protect threatened and endangered bat species. In my job, I help businesses and organizations by performing bat assessments and management plans.

Managing bats is about more than pest control. Remember, many bat species are protected. If you’re a building owner or manager dealing with bats, you have certain responsibilities.

Luckily, we have a new tool that can help us clearly identify if you have protected bat species on your site, and we can do it definitely and safely, without risk to the bats—we sample for eDNA, or environmental DNA.

 

How eDNA helps

What is eDNA? Well, organisms in the air, on land, and in water, all naturally shed DNA into their environment, such as in streams, rivers, oceans, or soils—even in fecal matter. By sampling the habitat where species live, we can detect their presence without having to capture, handle, or even see the organisms we are looking for. How do we use this process to help us identify potentially protected bat species? Our team calls the process “Bats from Scats.” We don’t have to visually see or capture the bat. We can analyze guano to determine the bat species that left it behind.

Before eDNA, the process to safely locate and identify a species was much more complex, time-consuming, and costly. Typically, my team and I would be outside, usually working with developers who want to identify if they have species at risk on their property, and to mitigate any impacts to those species during construction and operations.

In these outdoor scenarios, we would use several methods to identify bats, including entry/exit surveys and swarming surveys where field surveyors identify potential roosting habitat and visually survey for flying bats.

We also use acoustic bat detectors. Humans can’t hear bats calling because their mating calls are at a frequency that our ears can’t detect. So, during mating season, we attach acoustic detectors to trees or bridges or other structures. We then analyze the recordings using a software program to narrow down which species of bat were calling, but even this process is subject to human error.

 

Now, more than ever, it’s important to limit interactions between humans and bats to prevent the spread of the new coronavirus.

 

What happens when the bats are indoors? Indoor environments present a host of unique challenges. First, we visually inspect the building, like what you might do when looking for mold or asbestos in a structure, and we also can use acoustic detectors to capture bat calls to identify the species.

Using an eDNA approach, we collect bat guano and analyze the DNA to determine exactly which bat species is present. There is no other conventional method, other than bat trapping, that can provide us with a positive species identification for bats. Bat trapping is a complex, costly process. It requires permits and approvals, is invasive, and presents the possibility of bat injury.

Now, more than ever, it’s important to limit interactions between humans and bats to prevent the spread of the new coronavirus; we are all in this together, bats and humans alike. eDNA sampling provides a noninvasive and accurate way to determine if protected bat species are occupying your building or structure. We can then develop a bat management plan to protect you and the bats.

Hopefully learning about this new technology—and considering the importance of bats in our ecosystems—has given you a new sense of appreciation for these often maligned, much misunderstood creatures.

If you have bats where you do not want them, eDNA will help us to safely identify protected bat species without causing harm. That will help valuable bat species to thrive, while also guarding human health. Contact me to learn more.

About the Author

Kim Wenborn

Kim Wenborn is a biologist, project manager, and environmental DNA (eDNA) innovator working from Ottawa, Ontario. Kim is passionate and driven to explore and test the limits of eDNA to provide solutions to clients’ species-related challenges.

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